DEPRESSION IN CAREGIVERS OF DEMENTED PATIENTS IS ASSOCIATED WITH ALTERED IMMUNITY - IMPAIRED PROLIFERATIVE CAPACITY, INCREASED CD8(-TRANSDUCTION MOLECULES (CD38(+)) AND A CYTOTOXICITY MARKER (CD56(+) CD8+)(), AND A DECLINE IN LYMPHOCYTES WITH SURFACE SIGNAL)

Changes in relevant immune parameters, including function, were found to be associated with depression in elderly caregiver wives of demente d patients. We studied the relationship between immune cell phenotype and T cell proliferative capacity of such caregivers to levels of stre ss and depression over the course of a support group intervention. The data indicate the strongest association between depression (of all st ress parameters) and impaired T cell proliferative capacity. Depressio n was also most strongly (of stress parameters) associated with a shif t in T cell populations with an increase in CD8(+) T cells, and a redu ced percentage of CD38(+) cells in both CD8(+) and CD4(+) T cell popul ations. Since CD38 is a signal transduction factor, it was interesting that a decreased percentage of CD38(+) cells correlated with impaired T cell function (proliferation). Another significant difference was t he reduction in natural killer (NK) cells as well as the percentage of the CD56(+) component of the CD8(+) population. This latter subset is important in MHC-unrestricted cytotoxicity, and has been found expand ed in healthy centenarians. This study shows that both chronic stress, and depression in particular, and age have deleterious effects on T c ells, and together could significantly contribute to the higher risk o f disease and mortality associated with being a caregiver of a demente d individual.